1890. 1 41 



species : — T. loceneri : bright green, back of meso- aud metatliorax and 

 abdominal segments tinted with brownish-grey. Head pale green ; 

 clypeus fuscous ; posterior part also fuscous, broken up into spots be- 

 hind the eyes. Prothorax fuscous ; four pale spots on back and two 

 pale patches on the sides. T. aureola : head and prothorax brown, 

 sprinkled with pale points, and pale about the eyes ; other segments 

 of a reddish-brown colour on back. The larvae of this species have 

 none of the pretty green colour usually so conspicuous in those of 

 the preceding species. 



The most noteworthy character in the nymphs is to be found in 

 the mandibles ; these consist of a long sub-triangular basal part, 

 whose inner margin is indistinctly serrate, and a slender distal part 

 ending in a hook. Labrum nearly semicircular ; a group of about five 

 hairs on either side near the base. The back of the abdomen has the 

 usual small corneous plates, and these are arranged in the following 

 manner : — 



2nd segment near its base with two nearly circular plates, which posteriorly bear 

 three or four backward directed teeth. 



3rd segment near its base with two nearly circular plates, which posteriorly bear 

 three or four backward directed teeth. 



4th segment near its base with two nearly circular plates, which posteriorly bear 

 four or five backward directed teeth. 



5th segment near its base with two nearly circular plates, which posteriorly bear 

 five or six backward directed teeth, on its hind margin with two large transverse 

 plates, which carry a comb-like row of six or so large teeth and a series of smaller 

 ones, all directed forward. 



6th segment with two narrow plates situated on the extreme anterior margin ; 

 their rounded anterior part almost overlaps the preceding segment, and that part 

 bears a semicircle of backward directed teeth, which are more upright than those on 

 the other segments. These plates are placed closer together than usual, and lie 

 between the two large transverse plates of segment five. 



7th and 8th segments as in 4th or 5th. 



The plates of 2nd segment are least conspicuous, and those of the 5th are rather 

 larger than the others. These details refer more exclusively to T. aureola ; in T. 

 wmneri the plates have usually a tooth or so more. The abdomen terminates in two 

 side processes rounded at the point, and bearing a pencil of long hairs ; these pro- 

 cesses are covered with minute points, which in certain aspects look like teeth. In 

 addition to these upper processes, the S nymphs have two rounded inferior lobes. 

 There are no external respiratory filaments present. 



Comparing the larvae of Tinodes with those of other genera of 

 the HydropsycMdiE, perhaps the most characteristic parts in Tinodes 

 are the maxillse and spinneret, the latter being especially peculiar ; 

 the anterior leers also are much stouter than is usual amongst the 



